Automatic gas-feed for vacuum-tubes.



D. MoF. MOORE. AUTOMATIC GAS FEED FOR VACUUM TUBES. APPLICATION FILEDMAYB, 1906.

Patented Dec. 5, 1911.

I I l ATTORNEYS "UNITED srarr agrum FFI E DANIEL MoFABLAN MOORE, orNEWARK, NEW JERSEY, assrenon ro MOORE Enncrema ned, on new YORK, N. Y.,A CORPORATION or Nuwronx.

AUTOMATIC GAS-FEED FOR VACUUM-TUBES.-

Specification of Letters Patent.

all whom itxmay concerns Be it known that I, DANIEL MCFARLAN Moore, acitizen of the United States, and a resident of Newark, in the county ofEssex and State of New Jersey, with post-office address 52 Lawrencestreet, have invented,

proved manner of automatically supplyingv the gas or vapor to thevacuous spaces so as to maintain the gas or vapor tension at the degreenecessary for standard luminosity.

In carrying out my invention I make use of some material whose porosityincreases with an increase of temperature and automatically increasesthe temperature of said material when the resistance of the gas-in thetube decreases due to changes of tension.

Said material may be for example platinum, palladium, platiniridium,nickel or iron.

In the preferred manner of carrying out my invention, the material isarranged to be.

heated by the discharge through the gas in the tube so as toautomatically permit gas to feed thereto in amount to restore the vacuumto the normal or desired degree of tension when its resistancedecreases. In the accompanying drawings, Figurel is a general sideelevation and partial section of an apparatus embodying my invention.Figs. 2 and 3 illustrate modifications of the invention. v

1 indicates a vacuum tube furnished with electrodes 2 of any kind-,- bymeans of which electric energy may be applied to the gaseous contentsfor rendering the same luminous.

Located in proper position to feel directly the increase in thetemperature of said gas,

due to increase in the flow of the electric ener conse uent on andecrease of.

obstacle to the free flow of gas into said tube Application filed May a,190s. Serial no. 515332.

from a body of gas maintained at higher tension thanthe tension of thegas within 1 said tube. I

In Fig. 1 the material forms .a hollow plug or tube; which is sealed inthe wall of the tube and projectsmofe or lessinto Patented Dec. 5,1911.1

the heated gas or vapor. The walls of said tube form a septum betweenthe vacuous spaces and spaces containing the gas-which is to be fed tothe tube to keepthe gaseous tension normal. Such gas may be supplied to.the interior of the plug or tube 4 through a ipe'5 connected either tothe atmosphere with agas tank, gas generator, gas converter or anysource ofgas as descri applications for patent filed by me Apnl 2,

ed in prior 1906, Nos. 309,283, 309,285, 309,286, and filed v February7, 1906, S. No. 299,884.

In the operation of the device, the septum I 4 is of limited porosityand allows gas to flow in limited amount-insufficient to, increase thetension of"the gas in the tube,

so long as the operation of the tube and flow of current therein remainnormal.

When the vacuum increases more current flows and the septum 4, becomingmore highly heated, expands and allows aninflux of gas which willrestore the tension to nor.- m'al. Less current will now flow, and thetube 4- be thereby permitted to decrease in temperature and cut down theflow. While I have shown the employment of such a septum heated directly.by the gas through i which the current of-the lamp flows, it might bearranged to'be heated indirectly by the flow of current, as for"instance,'in the manner illustrated 1n Flg. 2, wherein-the circ-ui t ofthe tube or lamp-is shown as includ- I at which the current flow andluminosity are greatest so that an increase of vacuum lowers theresistance and causes more current to flow through the tube with anattendant increase of temperature and porosity in the material.

A further modification of my invention is 0011 open.

illustrated in .Fig. In this case-the increased flow of current in thelamp is used by the intervention of an electromagnet 11 to close anindependent circuit containing a heating coil which heats the septum orother form of porous substance which allows gas to leak. So long asthe-gas'tension in the tube remains at normal, the armature of themagnet being properly adjusted, will be in position to keep the circuitof the heating On decrease of tension in the tube and consequentincreaseof flow of cur.-, rent, the magnet will close the heating cirscuitand keepit closed untilsuflicient gas has been permitted to leakthrough the septum. to restore the tensionto normal. When this occurs,the armature" will drop back and open the heating circuit, thus cuttingdown the feed of-gas. Y

What I claim as my'invention is 1. The combination with a' Vacuum tubeautomatically upon a decrease of resistance ot the gas due to anincrease of vacuum atous tension and throwing it out of action when thegaseous tension increases sulficiently to increase the electricresistance to. normal.

l 3, The method of maintaining a constant luminosity in a. vacuum tubelamp by automatically "increasing the temperature and oros ty of amaterial interposed in the gas eed upon a decrease Oftheinternalresistance' due todecrease of the gaseous tension and vice versa.

Signem at New York in the county of New Yorkand' State of New York, this5th day of May A. D. 1906.

DANIEL'MGFARLAN MOORE.

Witnesses: a

" O. F. TISCHNER, J r.,

.LILLIAN BLOND.

